docs: def _filters(self):
          """
          Additional filters to:
              - select particular todo items given with the -i flag,
              - hide appropriately tagged items in the absense of the -x flag.
          """
          filters = super()._filters()
  
          if self.ids:
              def get_todo(p_id):
                  """
                  Safely obtains a todo item given the user-supplied ID.
                  Returns None if an invalid ID was entered.
                  """
                  try:
                      return self.todolist.todo(p_id)
                  except InvalidTodoException:
                      return None
  
              todos = [get_todo(i) for i in self.ids]
              filters.append(InstanceFilter(todos))
  
          if not self.show_all:
              filters.append(HiddenTagFilter())
  
          return filters